The present invention broadly relates to an internal combustion engine having a fuel injection system and, more particularly, to a fuel injection system which is suitable for use in an automotive gasoline engine which is specifically required to operate stably at low speed.
Automotive gasoline engines sometimes experience unstable operation when the engine speed is lowered by a release of the accelerator pedal, or when idling.
In order to overcome this problem, hitherto, it has been proposed to effect, when the engine speed is lowered, a rich compensation in response to an idle signal, as in Japanese Patent Laid-Open Nos. 231144/1984 and 30446/85.
Such proposed methods, however, do not contribute to improvement in the operation characteristics after the steady engine operation is achieved.